Animating a snowboarder
I think you'd be better off using a character animation technique over a constraints-based setup.  Why not use something like Rigify to quickly animate the character, and then use a very simple rig to bend the board.

I first learned Rigify with this tutorial: Quick Rigging with Rigify

As for bending the board, simply make an armature along the board with as many segments as you want.  Then, parent with automatic weight the board to the armature.  If you want, you can set up an IK Chain to make the bending a bit more realistic.

Use the Action Editor to make actions for the board and the character, then put them together with the NLA Editor.